What are some alternatives?
When comparing Gucharmap and PopChar, you can also consider the following products
WinCompose - WinCompose supports the standard Compose file format.
Event Viewer - Get help, support, and tutorials for Windows products—Windows 10, Windows 8.1, Windows 7, and Windows 10 Mobile.
BabelMap - Unicode Character Map for Windows
SymbSearch - A tool for searching unicode-symbols and copying it to the clipboard.
Shapecatcher - You need to find a specific Unicode character? With Shapecatcher.com you can search through a database of characters by simply drawing your character into a box. It can find the most similar character shapes for your drawing.
Rocket - Web Framework for Rust